//
// Created by Thinkpad on 2025/11/9.
//

#include <iostream>
using  namespace std;

const double PI = 3.141592653589;
class  Cylinder {
public:
    double base_radius{1.0};
    double height{1.0};

public:
    double volume() {
        return  PI * base_radius * base_radius * height;
    }
};


int main() {

    Cylinder cylinder1;
    cout << "volume : " << cylinder1.volume() << endl;

    return 0;
}